This invention relates generally to antennas, and more particularly, to antennas in wireless communications adapters for portable electronic devices.
As integrated circuit technology advances, it is becoming feasible to construct portable wireless devices with small form factors. Examples of portable wireless devices include mobile telephones, wireless headsets, digital cameras with wireless capabilities, remote controls, wristwatch-type devices, music players with wireless functions, and handheld computers. Devices such as these are often small enough to be held in the hand and may sometimes be referred to as handheld electronic devices. Larger portable wireless devices include laptop computers.
Portable electronic devices sometimes use antennas to transmit and receive radio-frequency signals. For example, handheld computers often contain short-range antennas for handling wireless connections with wireless access points. Other portable electronic devices have no built-in wireless communications capabilities or have only limited wireless functions.
In situations in which a portable electronic device does not have sufficient built-in wireless capabilities, a wireless communications adapter may be used to supply the portable electronic device with wireless communications capabilities.
It is generally desirable for an antenna in a wireless communications adapter for a portable electronic wireless device to exhibit a high efficiency. Antennas with high efficiencies are less likely to consume excessive power than inefficient antennas and are therefore able to operate using smaller power supplies. Large bandwidths are also sometimes desired. At the same time, it is generally desirable to make wireless communications adapters as small as reasonably possible. To a large extent, these requirements compete with each other. Conventional antenna arrangements that are small tend not to be efficient and have small bandwidths, whereas efficient wideband antennas tend to take up a fairly large volume.
It would therefore be desirable to be able to provide improved antennas for wireless communications adapters for portable electronic devices.